Cutting apparatus having disposable handpiece

Abstract

Apparatus and methods for intraoperatively performing surgery to create transmural channels in tissue, for example, as in transmyocardial revascularization, are provided using apparatus including a single-use handpiece having a mechanical cutting head and means for stabilizing the cutting head in contact with the tissue. The handpiece is coupled by a disposable cable to a controller that houses a vacuum pump and mechanisms for driving the cutting head. The cutting head is adapted to cooperate with the vacuum pump to evacuate tissue severed during the channel forming process.

What is claimed is: 
     
       1. Apparatus for use with a first vacuum source to form a channel in tissue, the apparatus comprising: a handpiece having: a body,   a shaft coupled to the body, the shaft including a lumen;   a cutting head having a bore coupled to the first vacuum source, a first position wherein the cutting head extends from within the lumen to form a channel in the tissue, tissue severed by the cutting head being aspirated through the bore by the first vacuum source, and a second position wherein the cutting head is retracted within the lumen; and   a tissue contacting element for stabilizing the cutting head in contact with the tissue.     
     
     
       2. The apparatus as defined in claim 1 wherein the apparatus further comprises: a controller housing a linear motor; and   a cable coupling the linear motor to the cutting head to move the cutting head between the first and second positions.   
     
     
       3. The apparatus as defined in claim 3 wherein the first vacuum source is housed within the controller. 
     
     
       4. The apparatus as defined in claim 1 further comprising a rotary motor disposed within the controller and coupled by the cable to the cutting head to rotate the cutting head. 
     
     
       5. The apparatus as defined in claim 4 wherein the handpiece further comprises a control panel having buttons that cause activation of the linear and rotary motors. 
     
     
       6. The apparatus as defined in claim 4 wherein the cable comprises a drive cable and the apparatus further comprises a coupling that transmits rotary motion and longitudinal motion from the rotary and linear motors, respectively, to the drive cable. 
     
     
       7. The apparatus as defined in claim 6 wherein the handpiece further comprises a spool coupled between the drive cable and the cutting head, the spool including struts defining apertures that permit passage of tissue aspirated through the bore of the cutting head to pass to a tissue filter. 
     
     
       8. The apparatus as defined in claim 1 wherein the shaft comprises a portion capable of articulating the cutting head to a position forming an angle relative to a longitudinal axis of the shaft. 
     
     
       9. The apparatus as defined in claim 1 wherein the cutting head, in the first position, also experiences motion selected from the group consisting of reciprocatory motion, angular motion or vibrational motion. 
     
     
       10. The apparatus as defined in claim 1 wherein the tissue contacting element comprises a suction cup disposed on the shaft near the cutting head and means for inducing suction through the suction cup. 
     
     
       11. The apparatus as defined in claim 10 wherein the first vacuum source provides a first level of suction to the cutting head and the means for inducing suction through the suction cup comprises a second vacuum source that provides a second level of suction, the second level of suction lower than the first level of suction. 
     
     
       12. The apparatus as defined in claim 10 further comprising means for selectively communicating suction induced by the means for inducing suction to the suction cup. 
     
     
       13. The apparatus as defined in claim 1 wherein the handpiece is discarded after a single use. 
     
     
       14. The apparatus as defined in claim 1 wherein the handpiece further comprises a drive tube coupled between the drive cable and the cutting head, the drive tube comprising: a rigid proximal portion;   a rigid distal portion; and   a flexible drive coupling disposed between the rigid proximal portion and the rigid distal portion.   
     
     
       15. The apparatus as defined in claim 1 further comprising means for advancing the cutting head at high speed in a distal direction. 
     
     
       16. The apparatus as defined in claim 1 further comprising: an EKG electrode disposed on the shaft to contact the tissue;   circuitry for monitoring electrical activity within the tissue; and   circuitry for triggering actuation of the cutting head responsive to detection of a predetermined feature of the electrical activity within the tissue.   
     
     
       17. The apparatus as defined in claim 1 further comprising: a transducer element disposed on the shaft to contact to the tissue, the transducer element generating a signal corresponding to a thickness of the tissue;   circuitry for computing a value of thickness of the tissue responsive to the signal generated by the transducer element; and   circuitry responsive to the circuitry for computing to automatically adjust a stroke length of the cutting head in the first position.   
     
     
       18. Apparatus for forming a channel in tissue, the apparatus comprising: a controller housing a linear motor and a first vacuum source;   a handpiece comprising: a body,   a shaft coupled to the body, the shaft including a lumen;   a cutting head having a bore coupled to the first vacuum source, a first position wherein the cutting head extends from within the lumen to form a channel in the tissue, tissue severed by the cutting head being aspirated through the bore by the first vacuum source, and a second position wherein the cutting head is retracted within the lumen; and   a tissue contacting element for stabilizing the cutting head in contact with the tissue; and   at least one cable coupling the linear motor and first vacuum source to the cutting head, the linear motor causing the cutting head to move the cutting head between the first and second positions.     
     
     
       19. The apparatus as defined in claim 18 further comprising a rotary motor housed within the controller and coupled by the cable to the cutting head to rotate the cutting head. 
     
     
       20. The apparatus as defined in claim 19 wherein the cable comprises a drive cable and the apparatus further comprises a coupling that transmits rotary motion and longitudinal motion from the rotary and linear motors, respectively, to the drive cable. 
     
     
       21. The apparatus as defined in claim 20 wherein the handpiece further comprises a spool coupled between the drive cable and the cutting head, the spool including struts defining apertures that permit passage of tissue aspirated through the bore of the cutting head to pass to a tissue filter. 
     
     
       22. The apparatus as defined in claim 18 wherein the shaft comprises a portion capable of articulating the cutting head to a position forming an angle relative to a longitudinal axis of the shaft. 
     
     
       23. The apparatus as defined in claim 18 wherein the cutting head, in the first position, also experiences motion selected from the group consisting of reciprocatory motion, angular motion or vibrational motion. 
     
     
       24. The apparatus as defined in claim 18 wherein the tissue contacting element comprises a suction cup disposed on the shaft near the cutting head and a second vacuum source housed in the controller that induces suction through the suction cup. 
     
     
       25. The apparatus as defined in claim 24 further comprising means for selectively communicating suction induced by the second vacuum source to the suction cup. 
     
     
       26. The apparatus as defined in claim 18 wherein the handpiece and cable are discarded after a single use. 
     
     
       27. The apparatus as defined in claim 20 wherein the handpiece further comprises a drive tube coupled between the drive cable and the cutting head, the drive tube comprising: a rigid proximal portion;   a rigid distal portion; and   a flexible drive coupling disposed between the rigid proximal portion and the rigid distal portion.   
     
     
       28. The apparatus as defined in claim 18 further comprising means for advancing the cutting head at high speed in a distal direction. 
     
     
       29. The apparatus as defined in claim 18 further comprising: an EKG electrode disposed on the shaft to contact the tissue;   circuitry for monitoring electrical activity within the tissue; and   circuitry for triggering actuation of the cutting head responsive to detection of a predetermined feature of the electrical activity within the tissue.   
     
     
       30. The apparatus as defined in claim 18 further comprising: a transducer element disposed on the shaft to contact to the tissue, the transducer element generating a signal corresponding to a thickness of the tissue;   circuitry for computing a value of thickness of the tissue responsive to the signal generated by the transducer element; and   circuitry responsive to the circuitry for computing to automatically adjust a stroke length of the cutting head in the first position.